Folder administrators, sub-administrators, group administrators, or group sub-administrators of the relevant folder can switch the settings.
▼ Set Up Approval Workflow (Web Browser)
https://teachme.jp/8/manuals/5839584
*If a group administrator or sub-administrator who is not a participant in the relevant folder performs the operation, they can enable (or disable) the approval workflow by opening the settings screen for the relevant folder from the group settings screen.
Related:
What is the Approval Workflow?